This invention relates to a method of moulding foamed porous pellets of synthetic resin of polyolefine.
Foamed polyolefines, such as polyethylene, are widely used in various applications; for example, as thermal insulators, cushions, packing materials, floating materials, sundry goods, building materials, etc. In these prior applications, the product is usually in the shape of plates, sheets, or films.
If other specially shaped products were desired, they were usually prepared from the plates, sheets or films, such as by cutting or scraping, and if necessary, adhering them to each other. But, such prior methods are tedious, and impractical to practice on an industrial scale and have much to be desired. In extreme cases, such methods are impossible to perform.
It is thus highly desirable to produce a moulded product of any finger or shape directly from the preliminary foamed resin pellets disposed in a mould. However, a method for production of a low density porous product with a desired complicated shape directly from foamable resin particles of polyolefines in a moulding process is not yet known due, it is thought, mainly to the technical difficulties involved.